function ReadQuotes() {  # Retrieve historical data for each ticker symbol  FS = ","  for (stock = 1; stock <= StockCount; stock++) {    URL = "http://chart.yahoo.com/table.csv?s=" name[stock] \          "&a=" month "&b=" day   "&c=" year-1 \          "&d=" month "&e=" day   "&f=" year \          "g=d&q=q&y=0&z=" name[stock] "&x=.csv"    printf("GET " URL " HTTP/1.0\r\n\r\n") |& YahooData    while ((YahooData |& getline) > 0) {      if (NF == 6 && $1 ~ /Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec/) {        if (stock == 1)          days[++daycount] = $1;        quote[$1, stock] = $5      }    }    close(YahooData)  }  FS = " "}function CleanUp() {  # clean up time series; eliminate incomplete data sets  for (d = 1; d <= daycount; d++) {    for (stock = 1; stock <= StockCount; stock++)      if (! ((days[d], stock) in quote))          stock = StockCount + 10    if (stock > StockCount + 1)        continue    datacount++    for (stock = 1; stock <= StockCount; stock++)      data[datacount, stock] = int(0.5 + quote[days[d], stock])  }  delete quote  delete days}function Prediction() {  # Predict each ticker symbol by prolonging yesterday's trend  for (stock = 1; stock <= StockCount; stock++) {    if         (data[1, stock] > data[2, stock]) {      predict[stock] = "up"    } else if  (data[1, stock] < data[2, stock]) {      predict[stock] = "down"    } else {      predict[stock] = "neutral"    }    if ((data[1, stock] > data[2, stock]) && (data[2, stock] > data[3, stock]))      hot[stock] = 1    if ((data[1, stock] < data[2, stock]) && (data[2, stock] < data[3, stock]))      avoid[stock] = 1  }  # Do a plausibility check: how many predictions proved correct?  for (s = 1; s <= StockCount; s++) {    for (d = 1; d <= datacount-2; d++) {      if         (data[d+1, s] > data[d+2, s]) {        UpCount++      } else if  (data[d+1, s] < data[d+2, s]) {        DownCount++      } else {        NeutralCount++      }      if (((data[d, s]  > data[d+1, s]) && (data[d+1, s]  > data[d+2, s])) ||          ((data[d, s]  < data[d+1, s]) && (data[d+1, s]  < data[d+2, s])) ||          ((data[d, s] == data[d+1, s]) && (data[d+1, s] == data[d+2, s])))        CorrectCount++    }  }}function Report() {  # Generate report  report =        "\nThis is your daily "  report = report "stock market report for "strftime("%A, %B %d, %Y")".\n"  report = report "Here are the predictions for today:\n\n"  for (stock = 1; stock <= StockCount; stock++)    report = report "\t" name[stock] "\t" predict[stock] "\n"  for (stock in hot) {    if (HotCount++ == 0)      report = report "\nThe most promising shares for today are these:\n\n"    report = report "\t" name[stock] "\t\thttp://biz.yahoo.com/n/" \      tolower(substr(name[stock], 1, 1)) "/" tolower(name[stock]) ".html\n"  }  for (stock in avoid) {    if (AvoidCount++ == 0)      report = report "\nThe stock shares to avoid today are these:\n\n"    report = report "\t" name[stock] "\t\thttp://biz.yahoo.com/n/" \      tolower(substr(name[stock], 1, 1)) "/" tolower(name[stock]) ".html\n"  }  report = report "\nThis sums up to " HotCount+0 " winners and " AvoidCount+0  report = report " losers. When using this kind\nof prediction scheme for"  report = report " the 12 months which lie behind us,\nwe get " UpCount  report = report " 'ups' and " DownCount " 'downs' and " NeutralCount  report = report " 'neutrals'. Of all\nthese " UpCount+DownCount+NeutralCount  report = report " predictions " CorrectCount " proved correct next day.\n"  report = report "A success rate of "\             int(100*CorrectCount/(UpCount+DownCount+NeutralCount)) "%.\n"  report = report "Random choice would have produced a 33% success rate.\n"  report = report "Disclaimer: Like every other prediction of the stock\n"  report = report "market, this report is, of course, complete nonsense.\n"  report = report "If you are stupid enough to believe these predictions\n"  report = report "you should visit a doctor who can treat your ailment."}function SendMail() {  # send report to customers  customer["uncle.scrooge@ducktown.gov"] = "Uncle Scrooge"  customer["more@utopia.org"           ] = "Sir Thomas More"  customer["spinoza@denhaag.nl"        ] = "Baruch de Spinoza"  customer["marx@highgate.uk"          ] = "Karl Marx"  customer["keynes@the.long.run"       ] = "John Maynard Keynes"  customer["bierce@devil.hell.org"     ] = "Ambrose Bierce"  customer["laplace@paris.fr"          ] = "Pierre Simon de Laplace"  for (c in customer) {    MailPipe = "mail -s 'Daily Stock Prediction Newsletter'" c    print "Good morning " customer[c] "," | MailPipe    print report "\n.\n" | MailPipe    close(MailPipe)  }}